150 research outputs found

    Guidelines for measuring and reporting environmental parameters for experiments in greenhouses

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    Background: The importance of appropriate, accurate measurement and reporting of environmental parameters in plant sciences is a significant aspect of quality assurance for all researchers and their research. There is a clear need for ensuring research across the world can be compared, understood and where necessary replicated by fellow researchers. A common set of guidelines to educate, assist and encourage comparativeness is of great importance. On the other hand, the level of effort and attention to detail by an individual researcher should be commensurate with the particular research being conducted. For example, a researcher focusing on interactions of light and temperature should measure all relevant parameters and report a measurement summary that includes sufficient detail allowing for replication. Such detail may be less relevant when the impact of environmental parameters on plant growth and development is not the main research focus. However, it should be noted that the environmental experience of a plant during production can have significant impact when subsequent experiments investigate plants at a molecular, biochemical or genetic level or where species interactions are considered. Thus, researchers are encouraged to make a critical assessment of what parameters are of primary importance in their research and these parameters should be measured and reported. Content: This paper brings together a collection of parameters that the authors, as members of International Committee on Controlled Environment Guidelines (ICCEG) in consultation with members of our three parent organizations, believe constitute those which should be recorded and reported when publishing scientific data from experiments in greenhouses. It provides recommendations to end users on when, how and where these parameters should be measured along with the appropriate internationally standardized units that should be used

    Gating of aquaporins by heavy metals in Allium cepa L. epidermal cells

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    Changes in the water permeability, aquaporin (AQP) activity, of leaf cells were investigated in response to different heavy metals (Zn2+, Pb2+, Cd2+, Hg2+). The cell pressure probe experiments were performed on onion epidermal cells as a model system. Heavy metal solutions at different concentrations (0.05 μM–2 mM) were used in our experiments. We showed that the investigated metal ions can be arranged in order of decreasing toxicity (expressed as a decrease in water permeability) as follows: Hg>Cd>Pb>Zn. Our results showed that β-mercaptoethanol treatment (10 mM solution) partially reverses the effect of AQP gating. The magnitude of this reverse differed depending on the metal and its concentration. The time course studies of the process showed that the gating of AQPs occurred within the first 10 min after the application of a metal. We also showed that after 20–40 min from the onset of metal treatment, the water flow through AQPs stabilized and remained constant. We observed that irrespective of the metal applied, the effect of AQP gating can be recorded within the first 10 min after the administration of metal ions. More generally, our results indicate that the toxic effects of investigated metal ions on the cellular level may involve AQP gating

    p21WAF1/CIP1 Upregulation through the Stress Granule-Associated Protein CUGBP1 Confers Resistance to Bortezomib-Mediated Apoptosis

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    p21(WAF1/CIP1) is a well known cyclin-dependent kinase inhibitor induced by various stress stimuli. Depending on the stress applied, p21 upregulation can either promote apoptosis or prevent against apoptotic injury. The stress-mediated induction of p21 involves not only its transcriptional activation but also its posttranscriptional regulation, mainly through stabilization of p21 mRNA levels. We have previously reported that the proteasome inhibitor MG132 induces the stabilization of p21 mRNA, which correlates with the formation of cytoplasmic RNA stress granules. The mechanism underlying p21 mRNA stabilization, however, remains unknown.We identified the stress granules component CUGBP1 as a factor required for p21 mRNA stabilization following treatment with bortezomib ( =  PS-341/Velcade). This peptide boronate inhibitor of the 26S proteasome is very efficient for the treatment of myelomas and other hematological tumors. However, solid tumors are sometimes refractory to bortezomib treatment. We found that depleting CUGBP1 in cancer cells prevents bortezomib-mediated p21 upregulation. FISH experiments combined to mRNA stability assays show that this effect is largely due to a mistargeting of p21 mRNA in stress granules leading to its degradation. Altering the expression of p21 itself, either by depleting CUGBP1 or p21, promotes bortezomib-mediated apoptosis.We propose that one key mechanism by which apoptosis is inhibited upon treatment with chemotherapeutic drugs might involve upregulation of the p21 protein through CUGBP1

    Life Cycle Impact Assessment

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    International audienceThis chapter is dedicated to the third phase of an LCA study, the Life Cycle Impact Assessment (LCIA) where the life cycle inventory's information on elementary flows is translated into environmental impact scores. In contrast to the three other LCA phases, LCIA is in practice largely automated by LCA software, but the underlying principles, models and factors should still be well understood by practitioners to ensure the insight that is needed for a qualified interpretation of the results.This chapter teaches the fundamentals of LCIA and opens the black box of LCIA with its characterisation models and factors to inform the reader about: (1) the main purpose and characteristics of LCIA, (2) the mandatory and optional steps of LCIA according to the ISO standard, and (3) the science and methods underlying the assessment for each environmental impact category. For each impact category, the reader is taken through (a) the underlying environmental problem, (b) the underlying environmental mechanism and its fundamental modelling principles, (c) the main anthropogenic sources causing the problem and (d) the main methods available in LCIA. An annex to this book offers a comprehensive qualitative comparison of the main elements and properties of the most widely used and also the latest LCIAmethods for each impact category, to further assist the advanced practitioner to make an informed choice between LCIA methods
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